Printing control apparatus, method for controlling printing control apparatus and storage medium

ABSTRACT

A printing control apparatus includes a conveying unit that conveys a document to a reading unit, a detection unit that detects a size of the document before it begins to be conveyed, a detection unit that detects the size of the document after the document begins to be conveyed, and a control unit that performs a copy job using the reading unit and printing unit based on the size of the document detected before it is conveyed in a case where the printing unit starts to print the image data before the reading unit finishes generating image data for one page and performs a copy job based on the size of the document detected after it begins to be conveyed in a case where the printing unit starts to print the image data after the reading unit finishes generating image data for at least one page.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is continuation of U.S. patent application Ser. No.16/587,859, filed Sep. 30, 2019; which is a continuation of U.S. patentapplication Ser. No. 15/971,699, filed May 4, 2018, now U.S. Pat. No.1,0469,687, issued Nov. 5, 2019; which is a continuation of U.S. patentapplication Ser. No. 14/964,415, filed Dec. 9, 2015, now U.S. Pat. No.9,992,366, issued Jun. 5, 2018, which claims the benefit ofInternational Patent Application No. PCT/JP2014/082992, filed Dec. 12,2014, which are hereby incorporated by reference herein in theirentirety.

TECHNICAL FIELD

Aspects of the present invention generally relate to a printing controlapparatus that reads an image on a document and prints the image on asheet.

BACKGROUND ART

In a printing control apparatus having a copy function, image data readby a reading unit is printed by a printing unit. As a method for readingan image on a document used at this time, a feed reading method isknown. In the feed reading method, a document is set on a documentsetting unit, and an image on the document is read at a fixed positionof an optical system while the document is being conveyed by a documentconveying unit (ADF: Auto Document Feeder).

In addition, a technique for reducing time (First Copy Out Time: FCOT)taken until a first sheet is output when an image on a document is readand the read image is printed on a sheet is known. Printing on the firstsheet is usually performed after reading of image data for one pageends. On the other hand, in PTL 1, reading of image data performed by areading unit and transfer of the image data to a printing unit areperformed as parallel processes, and printing starts before reading ofimage data for one page ends, in order to reduce the FCOT. In addition,in PTL 2, a printing control apparatus that determines, after a startbutton is pressed, whether job settings correspond to an FCOT mode isdescribed. This printing control apparatus determines that the jobsettings correspond to the FCOT mode if parameters set for a job arecertain parameters, such as the size of a document being A4, a readingscaling factor being 100%, a specified tray being a tray closest to aprinting unit, and the size of a sheet being A4, and performs controlfor reducing the FCOT.

If the FCOT is to be reduced by starting printing without until readingof image data for one page ends, parameters relating to a readingprocess and a printing process need to be determined before a copy jobstarts. A reading size of a document, for example, needs to bedetermined as one of the parameters.

In addition, in a copying process, an operation for starting printingwithout waiting until reading of image data for one page ends might notbe possible. If a function such as “scaling”, in which printing isperformed after the size of an image is changed, or “page integration”,in which a plurality of pages are laid out on a surface of a sheet, isset, for example, processing on an image needs to be performed afterimage data for one page is read. Printing can therefore start only afterthe reading of the image data ends.

In addition, the following two types of method are known as a method forautomatically detecting the size (document length and document width) ofa document to be read by the ADF. A first method is a method in whichthe size of a document is detected by a sensor provided on the documentsetting unit. In addition, a second method is a method in which the sizeof a document is detected by a sensor provided along a conveying path.

If the size of a document is detected by the sensor on the documentsetting unit, the size of the document can be detected before readingstarts, and the FCOT can be reduced using the above-described method. Ifthe size of a document is detected on the document setting unit,however, erroneous detection might occur.

If the size of a document is detected on the document setting unit, amethod for detecting the size of a sheet on the basis of whether aprotrusion on the document setting unit is pressed by the sheet, forexample, is used. In this method, however, the size of a document iserroneously detected if a rounded document (a curled document in thefollowing description) or a document with a fold (a folded document inthe following description) is set with part of the document not inplace. In this case, for example, a curled document of A3 size iserroneously detected as having A4 size, and printing is performed withpart of the actual document missing although the document of A3 size iscopied.

On the other hand, if the method in which the size of a document isdetected in the conveying path is used, the size of the document can becorrectly detected even if the above-mentioned curled document or foldeddocument is read. Since the size of the document is not detected beforea starting of reading, however, the FCOT cannot be reduced using theabove-described method.

Aspects of the present invention are established in view of the aboveand provide a mechanism for dynamically selecting a method for detectingthe size of a document in accordance with conditions.

CITATION LIST Patent Literature

PTL 1: Japanese Patent Laid-Open No. 2002-314763

PTL 2: Japanese Patent Laid-Open No. 2006-135702

SUMMARY OF INVENTION

A printing control apparatus according to an aspect of the presentinvention includes a reading unit for reading an image on a document andgenerating image data and a printing unit for printing the imageperforms a copy job using the reading unit and the printing unit. Theprinting control apparatus includes a conveying unit for conveying adocument set on a document setting unit to the reading unit, a firstdetection unit for detecting a size of the document set on the documentsetting unit before the conveying unit starts to convey the document, asecond detection unit for detecting the size of the document after theconveying unit starts to convey the document, and a control unit forperforming the copy job based on the size of the document detected bythe first detection unit in a case where the printing unit starts toprint the image data before the reading unit finishes generating imagedata for one page and performing the copy job based on the size of thedocument detected by the second detection unit in a case where theprinting unit starts to print the image data after the reading unitfinishes generating image data for at least one page.

Further features of the present disclosure will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram illustrating the configuration of an MFP 101.

FIG. 2 is a cross-sectional view illustrating the configuration of theMFP 101.

FIG. 3 is a diagram illustrating the appearance of an ADF 126.

FIG. 4 is a diagram illustrating a data model of a size detection table.

FIGS. 5A and 5B are diagrams illustrating the configuration of a readingunit 118.

FIGS. 6A and 6B are flowcharts illustrating a control method forcontrolling execution of copying.

FIGS. 7A and 7B are flowcharts illustrating a control method forcontrolling execution of copying.

FIGS. 8A to 8C are flowcharts illustrating a control method forcontrolling execution of copying.

FIG. 9 is a diagram illustrating an operation screen displayed on anoperation unit 116.

FIGS. 10A and 10B are conceptual diagrams of a copying process.

FIG. 11 is a diagram illustrating an example of operation conditions foran FCOT priority mode.

FIG. 12 is a diagram illustrating an operation screen displayed on theoperation unit 116.

DESCRIPTION OF EMBODIMENTS

Embodiments of the present invention will be described in detailhereinafter with reference to the drawings. It is to be noted that thefollowing embodiments do not limit aspects of the invention according tothe claims, and not all combinations of characteristics described in theembodiments are needed to implement aspects of the present invention.

First Embodiment

First, a first embodiment will be described. FIG. 1 is a block diagramillustrating the hardware configuration of a printing control apparatusaccording to the present embodiment. In addition, FIG. 2 is across-sectional view of the hardware configuration of the printingcontrol apparatus according to the present embodiment. An MFP(Multifunction Peripheral) 101 will be described in the presentembodiment as an example of the printing control apparatus.

The MFP 101 has a reading function of reading an image on a document andgenerating image data and a printing function of printing the image on asheet on the basis of the generated image data. It is to be noted thatsheets include print sheets such as plain paper and thick paper, OHPsheets, and the like. It is to be noted that the MFP 101 may have apost-processing function of binding a plurality of sheets on whichimages have been printed, lining up a plurality of sheets, ordistributing discharge destinations of a plurality of sheets to aplurality of discharge units. Furthermore, the MFP 101 may have a printfunction of receiving a print job from an external apparatus such as aPC and performing printing on a sheet on the basis of the print job. Itis to be noted that although an MFP is described in the presentembodiment as an example, aspects of the present invention can also beapplied to, for example, a copying machine having a single copyfunction.

A control unit 110 including a CPU 111 controls the operation of theentirety of the MFP 101. The CPU 111 reads a control program stored in aROM 112 or a storage 114 and performs one of various types of control,such as reading control, printing control, or copying control. In theROM 112, a control program that can be executed by the CPU 111 isstored. A RAM 113 is a main storage memory of the CPU 111 and used as atemporary storage area into which a control program stored in a workarea or the storage 114 is loaded. In the storage 114, image data,printing data, various programs, various pieces of history information,various pieces of setting information, and the like are stored. Inaddition, in the storage 114, the number of sheets subjected to printingperformed by a printing unit 120, counter information relating tocharging, and the like are stored. Although an auxiliary storage devicesuch as an HDD is assumed as the storage 114 in the present embodiment,a flash disk represented by an SSD may be used instead of the HDD.

It is to be noted that although a single CPU 111 performs variousprocesses described in flowcharts that will be referred to later using asingle memory (RAM 113) in the MFP 101 according to the presentembodiment, another mode may be implemented, instead. A plurality ofCPUs, RAMS, ROMs, and storages, for example, may cooperatively performthe various processes described in the flowcharts that will be referredto later. Alternatively, part of the processes may be performed using ahardware circuit such as an ASIC or an FPGA.

An operation unit I/F 115 connects an operation unit 116 and the controlunit 110 with each other. The operation unit 116 displays information toa user and receives an instruction from the user. For these purposes,the operation unit 116 includes a touch panel display that displays anoperation screen that will be described later and various hard keysincluding a start button and a setting button. The user inputs aninstruction using keys displayed on the touch panel display or thevarious hard keys. Alternatively, the operation unit 116 may include anindication display and various hard keys instead of the touch paneldisplay. In this case, the user inputs an instruction using the hardkeys. Alternatively, the operation unit 116 may be configured only bythe touch panel display.

A reading unit I/F 117 connects a reading unit 118 and the control unit110 with each other. The reading unit 118 reads an image on a documentand converts the image into image data such as binary data. The imagedata generated by the reading unit 118 is transferred to an imageprocessing section 125 through the reading unit I/F 117. Image datasubjected to image processing such as binarization or a rotation processperformed by the image processing section 125 is usually compressed by acompression/expansion section 124 and stored in the storage 114 of thecontrol unit 110. The image data is transmitted to an external apparatusthrough a communication unit I/F 123 or printed on a sheet. It is to benoted that if a copying process is performed in an FCOT priority mode,which will be described later, the reading of a document performed bythe reading unit 118 and the printing of the document that is being readcan be performed in parallel with each other.

In addition, the reading unit 118 includes an ADF 126. The ADF 126 feedsa document 32 in accordance with a control command from the reading unit118. The operation of the ADF 126 will be described with reference toFIG. 2.

A printing unit I/F 119 connects the printing unit 120 and the controlunit 110 with each other. Image data to be printed (image data that is aprint target) is transferred from the control unit 110 to the printingunit 120 through the printing unit I/F 119. The printing unit 120receives a control command from the CPU 111 and the image data to beprinted and prints an image based on the image data on a sheet such as aprint sheet.

A sheet processing unit I/F 121 connects a sheet processing unit 122 andthe control unit 110 with each other. The sheet processing unit 122receives a control command from the CPU 111 and performs post-processingon a sheet subjected to the printing performed by the printing unit 120in accordance with the control command.

In addition, the control unit 110 is connected to a network or the likethrough the communication unit I/F 123. The communication unit I/F 123transmits image data and information to an external apparatus (a mailserver, a file server, a PC, or the like) on a LAN (not illustrated) andreceives image data and information from the external apparatus on theLAN. Furthermore, the communication unit I/F 123 communicates with anexternal apparatus through a network such as a wireless LAN (notillustrated) or an external apparatus through a local interface such asUSB.

The compression/expansion section 124 performs a process for compressingor expanding image data or the like stored in the RAM 113 or the storage114 using one of various compression methods, such as JBIG or JPEG. Theimage data compressed or expanded by the compression/expansion section124 is stored in the RAM 113 or the storage 114 again.

The image processing section 125 performs an image conversion process onimage data stored in the RAM 113 or the storage 114 in accordance withregister values stored in the image processing section 125 and thenstores the converted image data in the RAM 113 or the storage 114 again.The CPU 111 sets the register values stored in the image processingsection 125 as necessary in order to perform desired image conversionprocess on image data. It is to be noted that the register values storedin the image processing section 125 include settings such as a colormode, a scaling factor (%) in an X direction, a scaling factor (%) in aY direction, reading resolution (pixels/inch), output resolution, and arotation angle (degrees).

Examples of the image conversion process include, for example, arotation process for rotating image data by a specified angle in unitsof blocks (e.g., by 32 pixels×32 pixels or so), a process for convertingresolution, a scaling process, a process for calculating a matrix of animage subjected to multi-value input, a process for converting colorspace, and the like.

Reading Realized Using Feed Reading Method

FIG. 2 is a cross-sectional view of the MFP 101. First, a feed readingmethod realized by the ADF 126 will be described. The ADF 126 includes adocument setting unit 201 for setting documents S consisting of one ormore documents. In addition, the ADF 126 includes a separation roller 2for feeding one of the documents S set on the document setting unit 201to a conveying path, a separation pad 21, and a pickup roller 1. Thepickup roller 1 comes into contact with a document surface of thedocuments S set on the document setting unit 201 and rotates. As aresult, documents on a top surface of the documents are fed to theconveying path. One of the documents fed by the power management system1 is separated by friction between the separation roller 2 and theseparation pad 21. In addition, a document detection sensor 14 isprovided downstream of the document setting unit 201 and can determinewhether a document is set on the document setting unit.

A multiple feeding detection sensor 13 determines whether the number ofdocuments separated by the separation roller 2 and the separation pad 21is 1. The multiple feeding detection sensor 13 is configured by anoscillation unit 13 a and a reception unit 13 b. The reception unit 13 breceives an ultrasonic wave output from the oscillation unit 13 a anddetermines whether the number of documents is 1 or more on the basis ofthe strength of received data. If multiple feeding of documents isdetected, the CPU 111 stops feeding documents and displays a jam (paperjam) screen on the operation unit 116.

The document that has passed through the multiple feeding detectionsensor 13 is conveyed toward register rollers 4 by a drawing roller pair3. The document comes into contact with the register rollers 4. As aresult, the document takes a form of a loop and diagonal feeding of thedocument is prevented. A feed path that conveys the document that haspassed through the register rollers 4 toward a document stage glass 203is provided downstream of the register rollers 4.

In addition, a control CPU (not illustrated) of the ADF 126 detects aleading edge of the document using a pre-register sensor 15 configuredby a photocoupler or the like in order to detect a timing of reading ofthe document or the like. The control CPU starts to count driving clocksof a conveying motor (not illustrated), which serves as a driving sourceof the rollers 3, 4, and 5 when the sensor 15 senses the leading edge ofthe document and turns on. The amount of movement of a document perdriving clock is always the same. By starting to count driving clockswhen the sensor 15 turns on, therefore, it is possible to measure howfar the document has been conveyed (a position of the leading edge ofthe document). The ADF 126 and the reading unit 118 start to read afront surface on the basis of a result of the measurement when theleading edge of the document conveyed from the document setting unit 201reaches a document front surface reading position on the glass 203. Inaddition, the ADF 126 and the reading unit 118 start to read a backsurface when the leading edge of the document conveyed from the documentsetting unit 201 reaches a document back surface reading position.

The document conveyed to the feed path is conveyed to a front surfacefeed reading position on the glass 203 by conveying rollers 5, anupstream roller 51, and a downstream roller 52. The document comes intocontact with the glass 203 while being sufficiently pressed by theupstream roller 51 and the front surface reading downstream roller 52.

When a timing of a starting of reading of the front surface comes, thereading unit 118 controls an optical unit (also referred to as a readingunit) 202 a. The optical unit 202 a includes light sources 211 a and 211b, mirrors 212 a, 212 b, and 212 c, and a line sensor 213. The readingunit 118 turns on the light sources 211 a and 211 b and radiates lightonto the document that is passing by a surface of the glass 203 atconstant speed. Light reflected from the document is incident on theline sensor 213 through the mirrors 212 a, 212 b, and 212 c. The linesensor 213 converts the light reflected from the document into anelectric signal. A CCD image sensor or the like, for example, is used asthe line sensor 213. An A/D converter, which is not illustrated,converts the electric signal into digital data (image data) and storesthe digital data in the storage 114 or the RAM 113 of the control unit110.

It is to be noted that, in the present embodiment, stick-shaped lightsources are used as the light sources 211 a and 211 b. A reading lineparallel to a longitudinal direction of the light sources 211 a and 211b is set, and image data is generated by conveying the document in adirection perpendicular to the reading line. It is to be noted that thelength of a document in a direction (main scanning direction) parallelto the reading line is defined as document width. In addition, thelength of a document in the direction (a conveying direction or asub-scanning direction) perpendicular to the reading line is defined asdocument length.

The document conveyed by the downstream roller 52 is conveyed to theback surface reading position on a glass 204 by conveying rollers 7, anupstream roller 53, and a downstream roller 54. The document comes intocontact with the glass 204 while being sufficiently pressed by theupstream roller 53 and the downstream roller 54. When a timing of astarting of reading of the back surface comes, the reading unit 118controls an optical unit 202 b to read an image on the document. It isto be noted that a reading method is the same as one adopted by theoptical unit 202 a. The document conveyed by the downstream roller 54passes by a discharge sensor 11 and is conveyed to a discharge unit 205by discharge rollers 12. It is to be noted that if only one surface of adocument is to be read, the document is discharged to the discharge unit205 without performing the reading of the back surface that wouldotherwise be performed by the optical unit 202 b.

In addition, the ADF 126 calculates the document length of the documenton the basis of time taken until a trailing edge of the document passesby the sensor 15 after the leading edge of the document passes by thesensor 15 and the conveying speed of the document. The control CPU ofthe ADF 126 obtains the number of driving clocks, for example, measureduntil the sensor 15 turns off after the sensor 15 senses the leadingedge of the document and turns on. The control CPU calculates thedocument length of the document on the basis of the number of drivingclocks obtained and the amount of movement that the document makes ineach driving clock because of the rollers. In addition, the ADF 126 candetect the document width using a document width detection sensor (notillustrated) provided along the conveying path. On the basis of acombination of these pieces of data, the size of the document can bedetected in the conveying path (a second detection unit in the followingdescription).

Although the calculation of the document length in the conveying path ofthe ADF 126 is realized using the above-described method in the presentembodiment, aspects of the present invention are not limited to this. Aprocess for correcting the document length, for example, may beperformed in consideration of slipping of a document that is beingconveyed, the component precision of the conveying rollers and thedocument conveying path, the meandering of a document in the documentconveying path, and the like. Furthermore, the document length may becalculated using another method, instead. Alternatively, the documentlength in the conveying path of the ADF 126 may be calculated using aplurality of sensors (e.g., sensors 15 to 18).

In addition, although the detection of the document width in theconveying path of the ADF 126 is realized using the above-describedmethod in the present embodiment, aspects of the present invention arenot limited to this. A result of detection of the document widthperformed by the width detection sensor of a guide 206 on the documentsetting unit 201, for example, may be used for the detection of thedocument width, instead.

As described above, in the feed reading method used by the ADF 126, aplurality of documents can be consecutively read by repeating anoperation for reading the documents S set on the document setting unit201 one by one and discharging the document to the discharge unit 205.It is to be noted that although an ADF that reads the front surface andthe back surface of a sheet in a single conveying path has beendescribed in the present embodiment as an example, aspects of thepresent invention are not limited to this. The present embodiment can beapplied even if, for example, an ADF reads the front and back of a sheetusing a single optical unit. In this case, a sheet may be reversed usinga reversal path (not illustrated) that reverses a sheet, and the opticalunit 202 a may read the sheet again.

Furthermore, the ADF 126 can detect the size of a document set on thedocument setting unit 201 (a first detection unit in the followingdescription).

FIG. 3 is a perspective view illustrating the document setting unit 201of the ADF 126. The document guide 206 is a guide used by the user toset documents on the document setting unit 201. The width detectionsensor (not illustrated) cooperates with the guide 206 to detect thedocument width of a document in accordance with a position of the guide206. It is to be noted that the user sets a document on the documentsetting unit 201 after adjusting the guide 206 to the width of the printsheet.

Sensors 207 and 208 are length detection sensors for detecting thedocument length of a document set on the document setting unit 201. Thesensors 207 and 208 protrude on an upper surface, for example, of thedocument setting unit 201 and output ON when pressed (208 in FIG. 2) bya document set. On the other hand, when not pressed, the sensors 207 and208 output OFF. The CPU 111 detects the document length by three levelsof resolution on the basis of outputs of the sensors 207 and 208.Although a configuration in which the sensor 207 and the sensor 208 areused for detecting the document length has been described in the presentembodiment, aspects of the present invention are not limited to this. Adetection method in which presence or absence of a document is opticallydetected or the like, for example, may be used, instead.

FIG. 4 is a diagram illustrating an example of a condition table fordetecting the size of a document set on the document setting unit 201.The CPU 111 refers to the table illustrated in FIG. 4 on the basis ofvalues detected by the width detection sensor of the guide 206, thesensor 207, and the sensor 208 in order to detect the size. It is to benoted that a document when short sides thereof are set parallel to theabove-mentioned reading line will be referred to as having an R size(A5R, A4R, or the like), and a document when long sides thereof are setparallel to the reading line will be referred to as A5, A4, or the like.In addition, since long sides of an A3 document or a B4 document cannotbe set parallel to the reading line, the A3 document or the B4 documentwill be simply referred to as “A3” or “B4” by omitting the R even whenshort sides thereof are set parallel to the reading line.

If the value detected by the width detection sensor is larger than 263.5mm and the sensors 207 and 208 are both ON, for example, the CPU 111detects the size as A3 (document width: 297 mm, document length: 420mm). On the other hand, if the value detected by the width detectionsensor is larger than a document width of 263.5 mm and the sensors 207and 208 are both OFF, the CPU 111 detects the size as A4 (documentwidth: 297 mm, document length: 210 mm).

As described above, if document widths of documents set on the documentsetting unit 201 are the same, whether the documents are setlongitudinally or laterally is determined on the basis of whether thesensors 207 and 208 are pressed.

Here, if the user sets a curled document, which has a rounded shape, ora folded document, which has a fold, on the document setting unit 201, atrailing edge of the document might float and not press the sensor 207or 208. In this case, the CPU 111 does not detect the size of theactually set document but erroneously detects that a document whose sizeis half the actually size is set.

It is to be noted that although size detection of an AB series has beendescribed in the present embodiment as an example, the size can bedetected with the same mechanisms even when an inch series or an AB/inchmixture series is adopted. In the case of the inch series, for example,the size can be detected by referring to a condition table for the inchseries. In addition, in the case of the AB/inch mixture series, the sizecan be detected by referring to a condition table for the mixtureseries.

Reading Realized Using Optical System Movement Method

Alternatively, reading can be performed by fixing the optical unit 202 aat the front surface reading position and setting a single document onthe glass 203 instead of performing a reading operation in which feedreading is performed (an optical system movement method in the followingdescription). In the case of this method, the document set on the glass203 is scanned while moving the optical unit 202 a in the sub-scanningdirection indicated by an arrow illustrated in FIG. 2. Light reflectedfrom the document is read by the line sensor 213 and converted intoimage data. It is to be noted that a white board 203 b is a white boardfor creating white-level reference data for correcting shading.

Next, a method for detecting the size of a document in the opticalsystem movement method will be described. FIG. 5A is a perspective viewillustrating the reading unit 118, and FIG. 5B is a plan view of theglass 203 of the reading unit 118 viewed from above.

As illustrated in FIG. 5A, the user can open and close the ADF 126 abouthinges 502. When the ADF 126 is open and the document stage 500 isexposed, the user can set a document on the glass 203. In addition, theADF 126 also functions as a pressure plate that fixes a document set onthe glass 203.

An open/close sensor 501 detects OFF if the angle of the ADF 126 isequal to or larger than a certain value (e.g., 15° or so) and detects ONif the angle is smaller than the certain value (that is, the ADF 126 isabout to be closed or closed).

If an output of the sensor 501 changes from OFF to ON, the CPU 111 turnson the light sources 211 a and 211 b and reads at least one line usingthe line sensor 213. The CPU 111 detects a portion in which light isblocked by and reflected from a document and a portion in which light isnot blocked and reflected light does not return because there is nodocument, in order to detect the document width of the document on thebasis of a result of the detection. On the other hand, the documentlength of the document is detected by a plurality of reflective sensors520 and 521 arranged as illustrated in FIG. 5B. The reflective sensors520 and 521 emit infrared light from their light-emitting units locatedbelow the document stage glass 203 and receive light reflected from thedocument using their light-receiving units. The CPU 111 detects thedocument length by three levels of resolution on the basis of outputs ofthe sensors 520 and 521. On the basis of the document width detected inthis manner and the document length detected by the three levels ofresolution, it is possible to detect which standard size a document has(a third detection unit in the following description).

It is to be noted that when the size of a still document set on thedocument stage glass 203 is detected, the ADF 126 functions as apressure plate that fixes the document set on the glass 203. When thesize of a document set on the document stage glass 203 is detected inthe present embodiment, therefore, it is assumed that a problem such asthe above-described curled document or folded document does not arise.

Printing Process

Returning to the description of FIG. 2, an operation (printingoperation) for outputting an image onto a sheet 221 using the printingunit 120 will be described.

A laser unit 222 converts image data into laser light on the basis ofthe image data transferred to the printing unit 120. The laser lightgenerated by the laser unit 222 is radiated onto photosensitive drums223 to 226, and electrostatic latent images according to the image dataare formed on the photosensitive drums 223 to 226 (exposure process).Developing units 227 to 230 apply toner (developer) to latent imageportions of the photosensitive drums 223 to 226 subjected to theexposure process using laser (developing process).

Next, the printing unit 120 feeds a sheet 221 from any of cassettes 251to 254 and a manual tray 250. The toner applied to the photosensitivedrums 223 to 226 is transferred to a first surface of the fed sheet 221(transfer process). The sheet to which the toner is applied through thetransfer process is conveyed to a fuser 233. The fuser 233 fuses theapplied toner on the sheet 221 with heat and pressure (fusing process).In the case of simplex printing, the sheet 221 that has passed throughthe fuser 233 is conveyed to the sheet processing unit 122 by conveyingrollers 234 and 235.

It is to be noted that, in the case of duplex printing, the sheet whosefirst surface has been subjected to the printing in the fuser 233 isconveyed to the reversal path, which is not illustrated, and reversed.The printing unit 120 prints an image corresponding to a next page on asecond surface (back surface) of the reversed sheet in the sameprocedure as for the first surface. The sheet 221 whose second surfacehas been subjected to the printing is conveyed to the sheet processingunit 122 by the conveying rollers 234 and 235.

It is to be noted that the cassettes 251 to 254 and the manual tray 250are paper feed trays (sheet feed unit). The cassettes 251 to 254 haveshapes of drawers, and a plurality of sheets can be stored therein. Onthe other hand, the manual tray 250 has an insertable shape, and aplurality of sheets 221 can be set therein.

The sheet conveyed to the sheet processing unit 122 is fed to a bufferunit 241. The buffer unit 241 can adjust conveying intervals of sheetsconveyed from a main body if the post-processing (e.g., a bindingprocess or a punch process) or the like performed downstream takes time.

The sheet that has passed through the buffer unit 241 is conveyed alonga conveying path 244 by an upstream discharge roller pair 242 and adownstream discharge roller pair 243 and temporarily stacked on a stacktray 245. If determining that sheets corresponding to one copy arestacked on the stack tray 245, the sheet processing unit 122 performsthe post-processing on the sheets. If the binding process is specifiedas a job, for example, a binding unit 246 performs the binding processon the sheets stacked on the stack tray 245. The sheets stacked on thestack tray 245 and subjected to the post-processing in accordance withjob settings is conveyed along a conveying path 248 and discharged to adischarge tray 247.

It is to be noted that if the MFP 101 does not include the sheetprocessing unit 122, a sheet that has passed through the fuser 233 isdischarged to a discharge unit (not illustrated) included in the MFP101. In addition, although a color MFP including four photosensitivedrums and four developing units has been described in the presentembodiment as an example, aspects of the present invention are notlimited to this. The MFP 101 may be a monochrome MFP including onephotosensitive drum and one developing unit. In addition, a printingmethod according to the present embodiment is not limited to anelectrophotographic method but may be another printing method such as aninkjet method or a heat transfer method.

Copying Process

In the present embodiment, when the MFP 101 performs the copyingprocess, control for selecting a method for detecting the size of adocument is performed in accordance with whether to perform an operationfor reducing the FCOT. FIGS. 6 to 8 are flowcharts illustrating controlof the copying process. Each operation (step) illustrated in theflowcharts of FIGS. 6 to 8 is realized when the CPU 111 has read acontrol program stored in the ROM 112 or the storage 114 to the RAM 113and executed. In addition, the flowcharts of FIGS. 6 to 8 are realizedwhen the control programs and components connected to the control unit110 cooperate with one another.

If the user selects copying on a main screen (not illustrated) displayedon the operation unit 116, the CPU 111 executes a control programindicated by the flowchart of FIG. 6(A). First, in step S601, the CPU111 controls the operation unit 116 such that an operation screen forsetting the copying is displayed. FIG. 9 is a diagram illustrating anexample of a copying screen. The user can set details of a copy jobthrough the screen illustrated in FIG. 9. Information 900 indicates thatexecution of a copy job can be started by pressing a start key (notillustrated) provided as a hard key outside the screen.

An operation key 911 is an operation key used for selecting an outputcolor of a print. The user operates the operation key 911 to selectblack and white, color, or automatic selection. It is to be noted thatif “automatic selection” is selected, the color of a document isautomatically identified from a read image. A color document can beoutput in colors, and a monochrome document can be output in monochrome.An operation key 912 is an operation key used for setting a scalingfactor for a print relative to the size of a document as no scaling. Onthe other hand, an operation key 913 is an operation key used forchanging the scaling factor for a print relative to the size of adocument to an arbitrary value. An operation key 914 is an operation keyused for selecting a print sheet used for printing. The user operatesthe operation key 914 to specify a print sheet (sheet) used for printingamong print sheets (sheets) associated with the paper feed trays (thecassettes 251 to 254 and the manual tray 250).

It is to be noted that information 901 notifies the user of settingsrelating to copying and the number of copies set with the operation key911 to the operation key 914. It is to be noted that the user can inputthe number of copies through a numeric keypad (not illustrated) providedas hard keys outside the screen.

An operation key 915 is an operation key used for setting finishing suchas the binding process, the punch process, or sorting for prints. Anoperation key 916 is an operation key used for setting reading of asurface of a document or reading of both surfaces of the document. Anoperation key 917 is an operation key used for setting a printingfunction for a copy job. The printing function is a function of printingand embedding a certain character string or mark or the like on imagedata generated by the reading unit 118.

An operation key 918 is an operation key used for reading documents ofdifferent sizes (mixed documents in the following description). Inaddition, an operation key 919 is an operation key for shifting to ascreen in which other settings relating to copying are made in additionto the currently displayed settings. In addition, by pressing the startkey provided as a hard key outside the screen, the user can start a copyjob.

Returning to the description of FIG. 6A, in step S602, the CPU 111determines whether a document is set on the ADF 126. If determining thata document is set on the ADF 126 in accordance with an output value ofthe document detection sensor 14, the CPU 111 proceeds to step S603. Ifdetermining that a document is not set, the CPU 111 proceeds to stepS604.

In step S603, the CPU 111 detects the size of the document set on thedocument setting unit of the ADF 126. The CPU 111 obtains output valuesof the width detection sensor, the sensor 207, and the sensor 208. Inaddition, the CPU 111 refers to the table illustrated in FIG. 4 as anexample using the obtained output values as conditions to detect thesize of a document corresponding to the conditions. The CPU 111 sets thedetected size of the document and a method in which the document set onthe ADF 126 is read as job parameters.

It is to be noted that the CPU 111 may detect the size of the documentagain if the output values of the sensor 207 and the sensor 208 change.Furthermore, if the output of the sensor 14 shifts to OFF, the CPU 111may remove a result of the detection of the size of the document andchange the method to be used to the method in which a document set onthe document stage is read.

It is to be noted that, in the present embodiment, the method in which adocument is read from the document stage glass 203 is set as a defaultparameter of the reading method. If a document is not set on the ADF126, therefore, the method in which a document is read from the documentstage glass 203 is set.

On the other hand, if detecting in step S604 that an output value of theopen/close sensor 501 changes from OFF to ON, the CPU 111 proceeds tostep S605. On the other hand, if the output value of the open/closesensor 501 does not change, the CPU 111 proceeds to step S606.

In step S605, the CPU 111 detects the size of a document on the documentstage glass 203. The CPU 111 obtains output values of the reflectivesensors 520 and 521 to detect the document length of the document. Inaddition, the CPU 111 reads an image for one line using the line sensor213 to detect the document width of the document, and detects the sizeof the document set on the document stage on the basis of the detecteddocument width and document length. The CPU 111 sets the detected sizeof the document and the method in which a document set on the documentstage glass 203 is read as job parameters.

It is to be noted that if the size of the document cannot be detected onthe basis of the document width and the document length, the CPU 111sets the reading method in which a document set on the document stage isread as a job parameter and issues an inquiry about the size of thedocument after receiving an instruction to start copying.

Next, in step S606, the CPU 111 receives settings for the copy jobthrough the screen illustrated in FIG. 9. In step S607, the CPU 111determines whether to operate in the FCOT priority mode on the basis ofthe copy job settings received in step S606 and the job parameters todetermine an operation mode of the copying process. Details will bedescribed with reference to the flowchart of FIG. 6B.

Next, in step S608, the CPU 111 determines whether the start key (notillustrated) has been pressed. The start key is provided on theoperation unit 116. If the start key has been pressed, the CPU 111proceeds to step S609. On the other hand, if the start key has not beenpressed, the CPU 111 returns to step S602.

In step S609, the CPU 111 performs a copying process in a normal mode ora copying process in the FCOT priority mode on the basis of theoperation mode determined in step S607 and ends the process. Details ofstep S609 will be described with reference to the flowcharts of FIGS. 7and 8.

Outline of FCOT Priority Mode

Copying operations according to the present embodiment include at leasttwo copying operations in the FCOT priority mode for reducing the FCOTand the normal copy mode. FIGS. 10A and 10B are conceptual diagramsschematically illustrating a copy control flow in the normal copy modeand a copy control flow in the FCOT priority mode. FIG. 10A illustratesthe copy control flow in the normal copy mode, and FIG. 10B illustratesthe copy control flow in the FCOT priority mode.

First, the normal copy mode will be described using FIG. 10A. In thenormal copy mode, printing in a printing process 1010 is performed afterreading in an image reading process 1000 is performed. The image readingprocess 1000 indicates a pipeline of the reading process, and theprinting process 1010 indicates a pipeline of the printing process. TheMFP 101 realizes the copying process by combining the image readingprocess 1000 and the printing process 1010 with each other.

In a reading unit process 1001, the reading unit 118 is controlled toread image data for certain lines. It is to be noted that the number ofcertain lines in the normal copy mode is appropriately set in accordancewith the size of a buffer memory set in accordance with the copy jobsettings, the performance of the image processing section 125, and thelike. The image data for certain lines is transferred to scan imageprocessing 1002. The scan image processing 1002 indicates imageprocessing performed by the image processing section 125, and image dataobtained by performing image processing on the image data for certainlines is stored in a buffer memory 1003. Buffer memories 1003 and 1005are secured in the RAM 113. The image data for certain lines stored inthe buffer memory 1003 is then compressed by the compression/expansionsection 124.

A compression process 1004 indicates the compression process performedby the compression/expansion section 124, in which the image data forcertain lines is subjected to coding, and a result of the process isstored in the buffer memory 1005. The image data for certain linesstored in the buffer memory 1005 is stored in an image storage area 1006of the storage 114. The CPU 111 repeats these pipeline processes tostore image data for one page in the image storage area 1006. After theimage data for one page is stored in the image storage area 1006, thepipeline process of the printing process starts. In the printing process1010, part of the image data stored in the image storage area 1006 isread to a buffer memory 1012. The read image data is expanded in anexpansion process 1013, subjected to image processing in print imageprocessing 1015, and transferred to a printing unit process 1016. Next,in the printing unit process 1016, the printing unit 120 is controlledto print the image data subjected to the image processing on a sheet.

Next, the FCOT priority mode will be described using FIG. 10B. The FCOTpriority mode is a mode in which writing of image data read by thereading unit 118 to the buffer memory 1003 and transfer of data from thebuffer memory 1003 to the printing unit are performed as parallelprocesses. In the FCOT priority mode in the present embodiment, data istransferred to the printing unit 120 without using the storage 114,whose access speed is lower than that of a memory area.

In the operation in the FCOT priority mode, the image reading process1000 and the printing process 1010 share the single buffer memory 1003.The image reading process 1000 starts to write the image data to thebuffer memory 1003. If image data of a certain size or larger is storedin the buffer memory 1003, the printing process 1010 starts to read theimage data from the buffer memory 1003 and performs the printingprocess. It is to be noted that the certain size is appropriately set inaccordance with parameters such as the reading speed of the reading unit118 and the image forming speed of the printing unit 120.

As described above, in the FCOT priority mode, image data starts to betransferred to the printing process 1010 and the printing process startswithout waiting until reading of image data for one page ends. The FCOTcan therefore be reduced by a length corresponding to time taken tocompress read image data and store the image data in the storage 114 andtime taken to load the image data from the storage 114 and expand theimage data. Since image data whose compression rate is low is sharedwith the printing process 1010, however, a large memory area needs to besecured.

In the operation in the FCOT priority mode, too, image data may bestored in the storage 114. These pieces of image data are used forrecovery or the like if, for example, the printing process 1010 is notcompleted due to an error such as a jam during image formation.

Determination of Copying Process Mode

Next, determination of a copying process mode will be described. FIG. 6Bis a flowchart illustrating control for determining whether to operatein the FCOT priority mode.

In step S611, the CPU 111 obtains job settings and parameters. In stepS612, the CPU 111 determines whether a sheet size and a paper feed trayare explicitly specified on the basis of the job setting informationobtained in step S611. It is to be noted that if the user selects aprint sheet (sheet) using the operation key 914, the sheet size and thepaper feed tray to be used for printing are explicitly set for the job.If determining that the sheet size and the paper feed tray arespecified, the CPU 111 proceeds to step S613 and sets a document sizespecification flag to ON as a job parameter. If determining that thesheet size and the paper feed tray are not explicitly specified, the CPU111 proceeds to step S614.

In step S614, the CPU 111 performs automatic paper feed cassetteselection (APS: Auto Paper Select) on the basis of the size of thedocument obtained in step S603 or step S605. The CPU 111 setsinformation regarding a paper feed cassette selected as a result of theAPS as a job parameter. It is to be noted that the APS is a function ofautomatically selecting a paper feed cassette in accordance with thesize of a document to be read and a specified scaling factor.

In step S615, the CPU 111 determines whether the APS has beensuccessful. If a paper feed cassette can be selected as a result of theAPS, the CPU 111 determines that the APS has been successful, andproceeds to step S616. On the other hand, if a paper feed cassettecannot be selected as a result of the APS, the CPU 111 determines thatthe APS has failed, and proceeds to step S618. In step S616, the CPU 111determines whether other operation conditions for the FCOT priority modeare satisfied.

In the present embodiment, there are some conditions for the operationin the above-described FCOT priority mode. FIG. 11 is a diagramillustrating an example of predetermined typical conditions for theoperation in the FCOT priority mode.

A first condition is that, as indicated by items 1101, settings relatingto the size of a document be made to satisfy conditions. As illustratedin FIG. 10B, in the FCOT priority mode, image data whose compressionrate is low needs to be shared between the reading unit 118 and theprinting unit 120, and larger memory than in the normal copy mode needsto be secured. The size of a document therefore needs to be determinedbefore a starting of execution of a job.

In addition, in order to perform the reading and the printing inparallel with each other, a timing at which a sheet is fed from a paperfeed tray, for example, needs to be advanced. Settings read duringexecution of a job, such as a paper feed cassette and a paper feed size,need to be made.

In addition, a document mixture mode is a mode in which documents ofdifferent sizes are read, and the sizes of the documents are detected bythe second detection unit in the conveying path. If the document mixturemode is set to ON, therefore, the operation in the FCOT priority mode isnot performed since sizes of documents cannot be determined before thestarting of the execution of a job.

A next condition is that, as indicated by items 1102, processing appliedto the entirety of a print page not be set. Settings such as scaling(enlargement or reduction) of an image, reduction layout, divisionreading, and image shifting, for example, are image processing performedon the entirety of image data. In addition, printing setting is afunction of superimposing a character string or an image on read imagedata. In addition, because order of pages read by the reading unit 118and order of pages to be printed are different from each other inbookbinding layout, a plurality of pieces of image data need to betemporarily accumulated in the storage or the like. If one of thesefunction is set, the reading and printing of image data cannot beperformed in parallel with each other, and the operation in the FCOTpriority mode is not performed.

In addition, the color mode needs to be set to color or monochrome. Ifautomatic selection is set as the color mode, the CPU 111 determinescolor pixels on the basis of color components (R, G, and B luminancesignals) of each pixel of a read document image and determines the colormode for performing the printing. If automatic selection is set,therefore, the operation in the FCOT priority mode is not performedbecause the reading and printing of image data cannot be performed inparallel with each other.

A last condition is that, as indicated by an item 1103, duplex printingnot be set. In the present embodiment, when a sheet is fed to theprinting unit 120, the CPU 111 sets control information regarding a pageto be printed on the sheet. If duplex copying is set, the operation inthe FCOT priority mode is not performed because priority is given totime taken to output sheets corresponding to one copy. Morespecifically, in the duplex copying in the present embodiment, a backsurface of the same sheet is reversed in the reversal path whileprinting is performed on a front surface of a next sheet, that is,distances between sheets passing along the conveying path are shortenedduring printing, in order to reduce copying time. The operation in theFCOT priority mode is therefore not performed.

It is to be noted that the conditions illustrated in FIG. 11 are anexample of typical conditions in the present embodiment, and aspects ofthe present invention are not limited to these.

Returning to the description of FIG. 6B, in step S616, if determiningthe operation conditions for the FCOT priority mode are satisfied, theCPU 111 proceeds to step S617 and sets the FCOT priority mode to ON. Onthe other hand, if determining that the operation conditions for theFCOT priority mode are not satisfied, the CPU 111 proceeds to step S618and sets the FCOT priority mode to OFF.

Copying Process

Next, the copying process will be described with reference to theflowcharts of FIGS. 7 and 8. FIGS. 7(A) and 8(A) are flowchartsregarding image reading control and flowcharts illustrating theoperation of a first program according to the present embodiment. Inaddition, FIG. 7B is a flowchart regarding printing control in thenormal copy mode and a flowchart illustrating the operation of a secondprogram according to the present embodiment. FIG. 8B is a flowchartregarding printing control in the FCOT priority mode and a flowchartillustrating the operation of a fourth program according to the presentembodiment. Furthermore, FIG. 8C is a flowchart regarding erroneousdetection control in the FCOT priority mode and a flowchart illustratingthe operation of a third program according to the present embodiment.

In the present embodiment, the first program, which performs the imagereading control, the third program, which performs control fordetermining erroneous detection, and the second and fourth programs,which perform the printing control, cooperate to realize the copyingprocess. If determining that the start key has been pressed (YES in stepS608), the CPU 111 starts to execute the first program corresponding tothe flowcharts of FIGS. 7(A) and 8(A).

First, a case in which the FCOT priority mode is OFF, that is, a case ofthe operation in the normal copy mode, will be described. In the normalcopy mode, after the reading control stores an image in the storage 114,the printing control performs printing.

In step S701, the CPU 111 determines whether the FCOT priority mode isON. If determining that the FCOT priority mode is ON, the CPU 111proceeds to the flowchart of FIG. 8A and performs copying in the FCOTpriority mode. On the other hand, if determining that the FCOT prioritymode is OFF, the CPU 111 proceeds to step S702.

In step S702, the CPU 111 controls the reading unit 118 and the imageprocessing section 125 on the basis of job settings and job parametersto prepare for reading of a document. If the method in which a documentis read from the ADF is set as a job parameter, for example, the CPU 111starts to feed a document and moves the optical unit 202 a to the frontsurface reading position. On the other hand, if the method in which adocument is read from the document stage is set as a job parameter, forexample, the CPU 111 moves the optical unit 202 a to a position at whichthe optical unit 202 a can read a document set on the document stageglass 203.

In step S703, the CPU 111 determines whether the document sizespecification flag is ON. If determining that the document sizespecification flag is ON, the CPU 111 proceeds to step S706. Ifdetermining that the document size specification flag is OFF, the CPU111 proceeds to step S704.

In step S704, the CPU 111 determines, on the basis of a job parameter,whether to read a document set on the ADF 126 or a document set on theglass 203. If the method in which a document set on the ADF 126 is readis set as a job parameter, the CPU 111 proceeds to step S705. On theother hand, if the method in which a document set on the document stageglass 203 is read is set as a job parameter, the CPU 111 proceeds tostep S706.

In step S705, the CPU 111 detects the size of the document to be read inthe conveying path using the second detection unit. The ADF 126, forexample, obtains the number of driving clocks measured until the sensor15 is turned off after the sensor 15 senses a leading edge of thedocument and turns ON. The ADF 126 multiplies the obtained number ofdriving clocks by the amount of movement of the document achieved by therollers per driving clock to calculate the document length of thedocument that is being conveyed. In addition, the ADF 126 can detect thedocument width of the document that is being conveyed using the documentwidth detection sensor (not illustrated) provided along the conveyingpath. The CPU 111 detects the size of the document in the conveying pathon the basis of the document length and the document width detected bythe ADF 126.

In step S706, a storage area for storing image data for certain lines issecured in the RAM 113 on the basis of the copy job settings andparameters.

In step S708, the reading unit 118 reads the document and generatesimage data. In step S709, the CPU 111 determines whether the image datafor certain lines has been generated. If determining that the image datafor certain lines has been generated, the CPU 111 proceeds to step S710.If determining that the image data for certain lines has not beengenerated, the CPU 111 returns to step S708. In step S710, thecompression/expansion section 124 codes and compresses the image datafor certain lines read by the reading unit 118. In step S711, thecompression/expansion section 124 stores the image data for certainlines compressed in step S710 in the image storage area of the storage114.

In step S712, the CPU 111 determines whether image data for one page hasbeen generated. If determining that image data for one page has beengenerated, the CPU 111 proceeds to step S713. On the other hand, ifdetermining that image data for one page has not been generated, the CPU111 returns to step S708 and obtains the image data by repeating stepS708 to step S711.

In step S713, the CPU 111 notifies the second program, which relates tothe printing control, that image data for one page has been generated.In addition, if the image data is a first page, the CPU 111 transmits,to the second program, which relates to the printing control,information indicating that the printing control is to start. It is tobe noted that if page integration or the like is set as a job setting,image data for a plurality of pages might be necessary to form an imageon a sheet. In this case, information indicating that the printingcontrol is to start may be issued after all pieces of image data for aplurality of pages to be printed on a sheet are obtained.

In step S714, the CPU 111 determines whether there is a next document.If reading a document set on the ADF 126, the CPU 111 determines whethera document is set on the ADF 126 on the basis of the output value of thesensor 14. If the output value of the sensor 14 is ON, the CPU 111determines that there is a next document, and returns to step S708. Onthe other hand, if the output value of the sensor 14 is OFF, the CPU 111determines that there is not a next sheet, and proceeds to step S715. Inaddition, if reading a document set on the glass 203 on the basis of jobparameters, the CPU 111 determines that there is not a next document,and proceeds to step S715.

In step S715, the CPU 111 notifies the second program that reading of adocument corresponding to a last page has ended, and ends the imagereading control. In addition, if reading a document set on the glass203, the CPU 111 determines that there is not a next document. The CPU111 then notifies the second program that the reading of the documenthas ended, and ends the image reading control.

Next, printing control during the operation in the normal copy mode willbe described. The flowchart of FIG. 7B illustrates the operation of thesecond program, which relates to the printing control in the normal copymode. After receiving, from the first program, which relates to thereading control, a notification indicating that the printing control isto start, the second program starts to perform control. When image dataused for performing printing on a first sheet has been generated, thefirst program issues the notification indicating that the printingcontrol is to start (step S713).

In step S720, the CPU 111 controls the printing unit 120 to prepare forthe printing by, for example, starting up the drums and warming up thefuser. In addition, the CPU 111 notifies, on the basis of the copy jobsettings and parameters, the printing unit 120 of the size of a sheet tobe fed and whether to perform image formation in colors or monochrome.After completing the preparation for the printing, the CPU 111 proceedsto step S721.

In step S721, the CPU 111 determines whether page data (image data forone page) that has not been output is stored in the image storage areaof the storage 114. If determining that page data that has not beenoutput is stored, the CPU 111 proceeds to step S721. On the other hand,if determining that page data that has not been output is not stored,the CPU 111 waits until page data that has not been output is generated.It is to be noted that, after receiving, from the first program, anotification indicating that image data for one page has been generated,the CPU 111 determines that page data that has not been output is newlystored in the storage area.

In step S722, the CPU 111 controls the printing unit 120 to performimage formation. More specifically, the CPU 111 loads compressed imagedata from the image storage area and, after expanding the compressedimage data, performs image processing in accordance with printingsettings and the like. The CPU 111 transfers the image data subjected tothe image processing to the printing unit 120. The printing unit 120feeds a sheet used for the printing from a paper feed tray and forms animage on the sheet by performing the above-described processes such asexposure, developing, transfer, and fusing.

In step S723, the printing unit 120 discharges the sheet subjected tothe printing to the discharge tray 247. It is to be noted that thepost-processing or the like is performed on a plurality of sheets on thebasis of the copy settings, the document is temporarily stacked on thestack tray 245. In this case, the post-processing is performed on thesheets after a last sheet is subjected to the printing, and the sheetsare discharged to the discharge tray 247.

In step S724, if determining that the notification (the notification instep S715) indicating that the reading of the document corresponding tothe last page has ended has been received from the first program andthat the printing of the page has been completed, the CPU 111 ends theprinting control. On the other hand, if the notification indicating thatthe reading of the document corresponding to the last page has ended hasnot been received from the first program, the CPU 111 returns to stepS721 and performs image formation for a next page and later.

It is to be noted that, in the normal copy mode, the printing controlillustrated in FIG. 7B may be performed after the reading of alldocuments is completed, instead, depending on the copy job settings. Ifduplex printing is set as a copy job, for example, image data for aplurality of pages needs to be accumulated since the same sheet isreversed while printing is being performed on a front surface of a nextsheet. The CPU 111 therefore performs the printing control illustratedin FIG. 7B after reading all the documents.

As described above, in the normal copy mode, printing is performed aftera document corresponding to at least one page is read.

Next, a case in which the FCOT priority mode is ON, that is, a case ofthe operation in the FCOT priority mode, will be described. In the FCOTpriority mode, the FCOT is reduced by starting to transfer image datafor one page to the printing unit 120 and starting the printing processbefore the reading unit 118 finishes reading the image data. In the FCOTpriority mode, the size of a document needs to be detected on thedocument setting unit 201 in order to advance a preparation operationfor transferring image data to the printing unit 120.

First, the operation of the first program, which relates to the imagereading control, will be described. In step S701, if determining thatthe FCOT priority operation is ON, the CPU 111 proceeds to the flowchartof FIG. 8A.

In step S800, the CPU 111 allocates an image data storage area in theRAM 113 on the basis of job settings and parameters. It is to be notedthat, in the FCOT priority mode, a storage area into which image datafor at least one page can be loaded is secured in order to forward imagedata read by the reading unit 118 to the printing unit 120 through thestorage area in the RAM 113.

In step S801, the CPU 111 controls the compression/expansion section124, the image processing section 125, the reading unit 118, and thelike on the basis of the copy job settings and parameters to prepare forreading of a document. If the method in which a document is read fromthe ADF is set as a job parameter, for example, the CPU 111 starts tofeed a document and moves the optical unit 202 a to the front surfacereading position. On the other hand, if the method in which a documentis read from the document stage is set as a job parameter, for example,the CPU 111 moves the optical unit 202 a to the position at which theoptical unit 202 a can read a document set on the document stage glass203.

In step S802, the CPU 111 determines whether the document sizespecification flag is ON. If determining that the document sizespecification flag is ON, the CPU 111 proceeds to step S805. Ifdetermining that the document size specification flag is OFF, the CPU111 proceeds to step S803.

In step S803, the CPU 111 determines, on the basis of a job parameter,whether to read a document set on the ADF 126 or a document set on theglass 203. If the method in which a document set on the ADF 126 is readis set as a job parameter, the CPU 111 proceeds to step S804. On theother hand, if the method in which a document set on the document stageglass 203 is read is set as a job parameter, the CPU 111 proceeds tostep S805.

In step S804, the CPU 111 notifies the third program, which relates tothe control for determining erroneous detection of the size of adocument, that the control is to start. In addition, the CPU notifiesthe third program of the size of the document detected on the documentsetting unit 201. The control for determining erroneous detection of thesize of a document will be described with reference to the flowchart ofFIG. 8C.

In step S805, the CPU 111 notifies the fourth program, which relates tothe printing control in the FCOT priority mode, that the control is tostart. In step S806, the CPU 111 notifies the fourth program, whichrelates to the printing control, of an address of the storage areasecured in step S800.

In step S807, the CPU 111 controls the reading unit 118 to read imagedata on the document. The read image data is transferred to the storagearea in the RAM 113. It is to be noted that speed at which the readingunit 118 reads image data is appropriately controlled such that thespeed does not become lower than speed at which the printing unit 120reads image data.

In step S808, the CPU 111 determines whether image data of a certainsize or larger has been stored in the storage area. If determining thatimage data of a certain size or larger has been stored in the storagearea, the CPU 111 proceeds to step S810. On the other hand, ifdetermining that image data of a certain size has not been stored in thestorage area, the CPU 111 proceeds to step S812.

In step S810, the CPU 111 determines whether the fourth program, whichrelates to the printing control, has been notified that the image dataof a certain size or larger corresponding to the document that is beingread has been stored. If the notification has not been issued, the CPU111 proceeds to step S811. If the notification has been issued, the CPU111 skips step S811 and proceeds to step S812.

In step S811, the CPU 111 notifies the fourth program, which relates tothe printing control, that the image data of a certain size or largerhas been generated. It is to be noted that the notification in step S811is used in the fourth program as a trigger to start to transfer theimage data to the printing unit 120.

In step S812, the CPU 111 determines whether image data for one page hasbeen generated. If determining that image data for one page has beengenerated, the CPU 111 proceeds to step S813. If determining that imagedata for one page has not been generated, the CPU 111 returns to stepS807 and continues to read the document. In step S813, the CPU 111notifies the fourth program that image data for one page has beengenerated.

In step S814, the CPU 111 determines whether the third program, whichrelates to the erroneous detection determination, has transmitted anotification of erroneous detection of the size. If determining that thethird program has transmitted a notification of erroneous detection ofthe size, the CPU 111 proceeds to step S815. If determining that thethird program has not transmitted a notification of erroneous detectionof the size, the CPU 111 proceeds to step S816.

In step S815, the CPU 111 controls the reading unit 118 to stop thereading control. It is to be noted that although reading of a next pageand later is stopped after reading and printing of a page in whicherroneous detection has occurred are completed if erroneous detection ofthe size occurs in the present embodiment, aspects of the presentinvention are not limited to this. The reading of the page, for example,may be stopped halfway, and image data that has already been read may beprinted on a sheet, instead. In this case, the first program dischargesa document that is being conveyed and ends the reading control.

In step S816, the CPU 111 determines whether there is a next document.If reading a document set on the ADF 126 and detecting a document set onthe ADF 126 on the basis of the output value of the sensor 14, the CPU111 determines that there is a next document, and returns to step S807.On the other hand, if determining that a document is not set on the ADF126 on the basis of the output value of the sensor 14, the CPU 111determines that there is not a next document, and proceeds to step S817.In step S817, the CPU 111 notifies the fourth program that reading of adocument corresponding to a last page has ended, and ends the imagereading control. In addition, if reading a document set on the glass203, the CPU 111 determines that there is not a next document. The CPU111 then notifies the fourth program that the reading of the documenthas ended, and ends the image reading control.

Next, the erroneous detection control during the operation in the FCOTpriority mode will be described. The flowchart of FIG. 8C illustratesthe operation of the third program, which relates to the erroneousdetection control. After receiving, from the first program, whichrelates to the reading control, the notification (the notification instep S804) indicating that the erroneous detection determination is tostart, the third program starts to perform control for determiningerroneous detection of the size of a document. In step S841, as in stepS705, the CPU 111 detects the size of the document to be read in theconveying path using the second detection unit.

In step S842, if determining that the size of the document detected bythe first detection unit is different from the size of the documentdetected in step S841, the CPU 111 proceeds to step S843. On the otherhand, if determining that the detected sizes of the documents are thesame, the CPU 111 proceeds to step S847.

In step S847, the CPU 111 determines whether the notification (thenotification in step S817) indicating that the reading of the documentcorresponding to the last page has ended has been received from thefirst program. If determining that the notification indicating that thereading of the document corresponding to the last page has ended hasbeen received, the CPU 111 ends the control for determining erroneousdetection. On the other hand, if determining that the notificationindicating that the reading of the document corresponding to the lastpage has ended has not been received, the CPU 111 returns to step S841.

In step S843, the CPU 111 notifies the first program, which relates tothe reading control, and the fourth program, which relates to theprinting control in the FCOT priority mode, that the size of thedocument detected on the document setting unit has been erroneouslydetected. It is to be noted that upon receiving the notification, thefirst program and the fourth program perform a process for stopping thecopy job.

In step S844, the CPU 111 controls the operation unit 116 to display anotification screen for notifying the user of the erroneous detection ofthe size of the document. FIG. 12 is a diagram illustrating an exampleof the notification screen. Information 1201 is information fornotifying the user that the size of the document has not been correctlydetected. An operation key 1211 is an operation key used for closing thenotification screen.

Returning to the description of FIG. 8C, in step S845, the CPU 111determines whether the key 1211 has been pressed. If the key 1211 hasnot been pressed, the CPU 111 returns to step S845 and waits until theuser presses the key 1211. If the key 1211 has been pressed, the CPU 111proceeds to step S846. In step S846, the CPU 111 closes the notificationscreen and ends the copying process.

As described above, if erroneous detection of the size of a documentoccurs in the FCOT priority mode, the user can be notified of theerroneous detection. It is to be noted that if erroneous detection ofthe size of a document occurs, the counter information relating tocharging stored in the storage 114 need not be updated.

Finally, the printing control during the operation in the FCOT prioritymode will be described. The flowchart of FIG. 8B illustrates theoperation of the fourth program, which relates to the printing controlin the FCOT priority mode. After receiving, from the first program,which relates to the reading control, the notification (the notificationin step S805) indicating that the printing control is to start, thefourth program starts the control.

In step S820, the CPU 111 controls the printing unit 120 to prepare forthe printing by, for example, starting up the drums and warming up thefuser. In addition, the CPU 111 notifies, on the basis of the copy jobsettings and parameters, the printing unit 120 of the size of a sheet tobe fed and whether to perform image formation in colors or monochrome.After completing the preparation for the printing, the CPU 111 proceedsto step S821.

In step S821, the CPU 111 shares the storage area transmitted from thefirst program, which relates to the reading control, with the firstprogram on the basis of the address (the notification in step S806) ofthe storage area.

In step S822, if receiving the notification (the notification in stepS811) indicating that image data of a certain size or larger has beengenerated has been received from the first program, the CPU 111 proceedsto step S824. On the other hand, if the notification indicating thatimage data of a certain size or larger has been generated has not beenreceived, the CPU 111 waits until a notification indicating that imagedata of a certain size or larger has been generated is received from thesecond program.

In step S824, the CPU 111 reads the image data of a certain size orlarger from the storage area and transfers the image data to theprinting unit 120. In step S825, the CPU 111 controls the printing unit120 to feed a sheet to be subjected to printing and performs theabove-described processes such as exposure, developing, transfer, andfusing on the basis of the transferred image data.

In step S826, if determining, on the basis of the notification (thenotification in step S813) indicating that image data for one page hasbeen generated from the first program, that image formationcorresponding to the image data has been completed, the CPU 111 proceedsto step S827. On the other hand, if the CPU 111 has not received, fromthe first program, the notification indicating that image data for onepage has been generated, the CPU 111 returns to step S824 and performsimage formation.

In step S827, the CPU 111 determines whether a notification of erroneousdetection of the size has been received from the third program, whichrelates to the erroneous detection determination. If determining thatthe notification of erroneous detection of the size has been received,the CPU 111 proceeds to step S828. If determining that the notificationindicating that erroneous detection of the size has not been received,the CPU 111 proceeds to step S829. In step S828, the CPU 111 controlsthe printing unit 120 to stop the image formation process. It is to benoted that although reading of a next page and later is stopped afterreading and printing of a page in which erroneous detection has occurredare completed if erroneous detection of the size occurs in the presentembodiment, aspects of the present invention are not limited to this.The image formation, for example, may be stopped after a notification oferroneous detection is received, and the sheet may be output, instead.In this case, if a notification of erroneous detection is receivedbefore the image formation in step S825, a blank sheet is output. Inaddition, if the CPU 111 receives a notification of erroneous detectionafter the image formation in step S825 starts, a sheet in which an imageis partly formed is output.

In step S829, if determining that the notification (the notification instep S817) indicating that the reading of the document has ended hasbeen received from the first program and the printing of the image datacorresponding to the last page has been completed, the CPU 111 ends theprinting control. On the other hand, if the CPU 111 has not received,from the first program, the notification indicating that the reading ofthe document has ended, the CPU 111 returns to step S822 and performsimage formation on a next sheet.

As described above, in the present embodiment, the method for detectingthe size of a document is automatically selected both when the operationfor reducing the FCOT is performed and when the operation for reducingthe FCOT is not performed. If the operation for reducing the FCOT isperformed, the size of a document detected by the first detection unitbefore conveying of the document starts is used, and the copying processcan be performed in the FCOT priority mode. On the other hand, if theoperation for reducing the FCOT is not performed, since the copyingprocess is performed using the size of a document determined by thesecond detection unit after conveying of the document starts, thecopying process can be performed using the correct document size.

Furthermore, in the present embodiment, if the copying process isperformed in the FCOT priority mode, the user can be notified thaterroneous detection of the size of a document has occurred. It istherefore possible to suppress output without the user knowing that partof the actual document is missing.

In addition, in the present embodiment, if erroneous detection of thesize of a document occurs in the FCOT priority mode, the counterinformation relating to charging stored in the storage 114 need not beupdated. It is therefore possible to suppress charging after a copyingprocess in which part of the document is missing due to erroneousdetection in the MFP occurs.

Other Embodiments

Aspects of the present invention can also be realized by a process inwhich a program that realizes one or more functions according to theabove embodiment is supplied to a system or an apparatus through anetwork or a storage medium and one or more processors in a computer ofthe system or the apparatus read and execute the program. In addition,aspects of the present invention can be realized by a circuit (e.g., anASIC) that realizes the one or more functions.

Although exemplary embodiments have been described in detail, aspects ofthe present invention are not limited to such particular embodiments andmay be modified and altered in various ways without deviating from thescope thereof described in the claims.

According to aspects of the present invention, if an operation forreducing the FCOT is performed by dynamically selecting the method fordetecting the size of a document in accordance with the conditions, thetime taken until a first sheet can be reduced. If the operation forreducing the FCOT is not performed, it is possible to prevent part of animage from missing.

While aspects of the present invention have been described withreference to exemplary embodiments, it is to be understood that theaspects of the invention is not limited to the disclosed exemplaryembodiments. The scope of the following claims is to be accorded thebroadest interpretation so as to encompass all such modifications andequivalent structures and functions.

1. A copier comprising: a conveyor for conveying, via a conveying path, a document sheet set on a document setting tray; at least one first sensor on the document setting tray; at least one second sensor in the conveying path; a reader which is able to read an image on the document sheet conveyed by the conveyor to generate image data; a controller that selects a print sheet based on a detection result of the at least one first sensor; a feeder that feeds the print sheet selected by the controller; a printer for printing the image based on the image data on the print sheet fed by the feeder, wherein the copier performs a copy job using the reader and the printer; and a display that displays, in a case where the feeder starts to feed the print sheet before the reader finishes generating image data for one page, a predetermined information based on the detection result of the at least one first sensor and a detection result of the at least one second sensor.
 2. The copier according to claim 1, wherein the display displays the predetermined information in a case where the feeder starts to feed the print sheet before the reader finishes generating image data for one page, and the detection result of the at least one first sensor is not same as the detection result of the at least one second sensor.
 3. The copier according to claim 1, wherein the display that displays, in a case where the feeder starts to feed the print sheet before the reader finishes generating image data for one page, the predetermined information based on the detection result of the at least one first sensor and the detection result of length of the document sheet by the at least one second sensor.
 4. The copier according to claim 1, wherein the predetermined information is for notifying a user that the document is folded.
 5. The copier according to claim 1, wherein the predetermined message is for urging a user to get folds out of the document.
 6. The copier according to claim 1, wherein the predetermined message is for urging a user to get folds out of the document.
 7. The copier according to claim 1, wherein the display further displays a message for urging a user to set a mixed document sizes mode.
 8. A copier comprising: a conveyor for conveying, via a conveying path, a document sheet set on a document setting tray; at least one first sensor on the document setting tray; at least one second sensor in the conveying path; and a reader which is able to read an image on the document sheet conveyed by the conveyor to generate image data; a controller that selects a print sheet based on a detection result of the at least one first sensor; a feeder that feeds the print sheet selected by the controller; and a printer for printing the image based on the image data on the print sheet fed by the feeder, wherein the copier performs a copy job using the reader and the printer, wherein, in a case where the feeder starts to feed the print sheet before the reader finishes generating image data for one page, the controller interrupts the copy job based on the detection result of the at least one first sensor and a detection result of the at least one second sensor.
 9. The copier according to claim 8, wherein the controller interrupts the copy job in a case where the first document size determined based on output from the at least one first sensor is not the second document size determined based on output from the at least one second sensor.
 10. The copier according to claim 8, wherein, in a case where the feeder starts to feed the print sheet before the reader finishes generating image data for one page, the controller interrupts the copy job based on the detection result of the at least one first sensor and the detection result of length of the document sheet by the at least one second sensor.
 11. The copier according to claim 8, further comprising a display that displays a predetermined information based on the first document size determined based on output from the at least one first sensor and the second document size determined based on output from the at least one second sensor.
 12. The copier according to claim 11, wherein the predetermined information is for notifying a user that the document is folded.
 13. The copier according to claim 11, wherein the predetermined information is for urging a user to get folds out of the document.
 14. The copier according to claim 11, wherein the predetermined information is for urging a user to get folds out of the document.
 15. A control method for controlling a copier comprising a conveyor for conveying, via a conveying path, a document sheet set on a document setting tray, at least one first sensor on the document setting tray, and at least one second sensor in the conveying path, the control method comprising: reading an image on the document sheet conveyed by the conveyor to generate image data; selecting a print sheet based on a detection result of the at least one first sensor; feeding the selected print sheet; printing the image based on the image data on the fed print sheet, wherein the copier performs a copy job including the reading and the printing; and displaying, in a case where the print sheet is fed before generating image data for one page is finished, a predetermined information based on the detection result of the at least one first sensor and a detection result of the at least one second sensor.
 16. A control method for controlling a copier comprising a conveyor for conveying, via a conveying path, a document sheet set on a document setting tray, at least one first sensor on the document setting tray, and at least one second sensor in the conveying path, the control method: reading an image on the document sheet conveyed by the conveyor to generate image data; selecting a print sheet based on a detection result of the at least one first sensor; feeding the selected print sheet; and printing the image based on the image data on the fed print sheet, wherein the copier performs a copy job including the reading and the printing; and interrupting, in a case where the print sheet is fed before generating image data for one page is finished, the copy job based on the detection result of the at least one first sensor and a detection result of the at least one second sensor. 